Familial dysbetalipoproteinemia

Familial dysbetalipoproteinemia

Familial dysbetalipoproteinemia, also known as type III hyperlipoproteinemia or remnant hyperlipidemia, is a rare genetic disorder characterized by abnormal lipid metabolism. It is caused by a mutation in the apolipoprotein E (apoE) gene, resulting in the accumulation of chylomicron remnants and very low-density lipoprotein (VLDL) remnants in the blood.

Signs and Symptoms

Individuals with familial dysbetalipoproteinemia often present with symptoms related to abnormal lipid levels, such as xanthomas (yellowish deposits of fat under the skin), tuberous xanthomas (nodules on the elbows and knees), and corneal arcus (a white or grayish ring around the cornea). They may also experience symptoms of cardiovascular disease, including chest pain, shortness of breath, and peripheral artery disease.

Pathophysiology

Familial dysbetalipoproteinemia is an autosomal recessive disorder, meaning that an affected individual must inherit two copies of the mutated apoE gene, one from each parent. The mutation leads to impaired clearance of chylomicron and VLDL remnants from the bloodstream, resulting in their accumulation. This accumulation leads to the formation of atherosclerotic plaques, which can narrow and block blood vessels, increasing the risk of cardiovascular disease.

Diagnosis

Diagnosis of familial dysbetalipoproteinemia is typically based on clinical presentation, lipid profile analysis, and genetic testing. A lipid profile will show elevated levels of cholesterol and triglycerides, particularly in the form of chylomicron and VLDL remnants. Genetic testing can confirm the presence of the apoE gene mutation.

Treatment

The primary goal of treatment for familial dysbetalipoproteinemia is to reduce lipid levels and prevent the development or progression of cardiovascular disease. This is typically achieved through lifestyle modifications, such as adopting a heart-healthy diet, engaging in regular physical activity, and maintaining a healthy weight. Medications, such as statins and fibrates, may also be prescribed to further lower lipid levels.

Prognosis

With appropriate management, individuals with familial dysbetalipoproteinemia can lead relatively normal lives. However, if left untreated, the disorder can lead to significant cardiovascular complications, including heart attacks and strokes. Regular monitoring of lipid levels and adherence to treatment recommendations are crucial for long-term management and prevention of complications.

See Also

• Hyperlipidemia
• Apolipoprotein E
• Chylomicron
• Very low-density lipoprotein
• Atherosclerosis